Use of Electromechanical Feedback in MEMS for Suppressing Electronics Noise

Abstract

At the pull-in point, a capacitive MEMS sensor becomes infinitely sensitive to applied force as the effective spring constant goes to zero because of electromechanical feedback We show that this phenomenon can be used to fully eliminate the noise contribution of readout electronics. Experimentally, we show that the electronics noise and interference contribution to system resolution could be suppressed by an order of magnitude, reaching the intrinsic resolution of the MEMS microphone. Experiments are in good agreement with a theory based on a small signal model of a harmonic MEMS oscillator. The technique allows the use of standard integrated electronics with noise-critical MEMS sensors, such as microphones, pressure sensors and accelerometers.

title = "Use of Electromechanical Feedback in MEMS for Suppressing Electronics Noise",

abstract = "At the pull-in point, a capacitive MEMS sensor becomes infinitely sensitive to applied force as the effective spring constant goes to zero because of electromechanical feedback We show that this phenomenon can be used to fully eliminate the noise contribution of readout electronics. Experimentally, we show that the electronics noise and interference contribution to system resolution could be suppressed by an order of magnitude, reaching the intrinsic resolution of the MEMS microphone. Experiments are in good agreement with a theory based on a small signal model of a harmonic MEMS oscillator. The technique allows the use of standard integrated electronics with noise-critical MEMS sensors, such as microphones, pressure sensors and accelerometers.",

T1 - Use of Electromechanical Feedback in MEMS for Suppressing Electronics Noise

AU - Helistö, Panu

AU - Sipola, Hannu

AU - Seppä, Heikki

PY - 2012

Y1 - 2012

N2 - At the pull-in point, a capacitive MEMS sensor becomes infinitely sensitive to applied force as the effective spring constant goes to zero because of electromechanical feedback We show that this phenomenon can be used to fully eliminate the noise contribution of readout electronics. Experimentally, we show that the electronics noise and interference contribution to system resolution could be suppressed by an order of magnitude, reaching the intrinsic resolution of the MEMS microphone. Experiments are in good agreement with a theory based on a small signal model of a harmonic MEMS oscillator. The technique allows the use of standard integrated electronics with noise-critical MEMS sensors, such as microphones, pressure sensors and accelerometers.

AB - At the pull-in point, a capacitive MEMS sensor becomes infinitely sensitive to applied force as the effective spring constant goes to zero because of electromechanical feedback We show that this phenomenon can be used to fully eliminate the noise contribution of readout electronics. Experimentally, we show that the electronics noise and interference contribution to system resolution could be suppressed by an order of magnitude, reaching the intrinsic resolution of the MEMS microphone. Experiments are in good agreement with a theory based on a small signal model of a harmonic MEMS oscillator. The technique allows the use of standard integrated electronics with noise-critical MEMS sensors, such as microphones, pressure sensors and accelerometers.